When having to develop a UE4 project that deals with a tiny world scale, like the whole level being less the 50cm size for example, The following steps may help make the project more easily navigate-able and convenient to work on.
Scale down the camera Icon: UE4 has by default a huge, bulky, opaque camera icon. For a tiny scale project, this camera icon may cover the whole level and be very inconvenient to work with. Select the relevant camera component and scale it down. In my tests, this modified camera matrix isn’t breaking the camera optics in any way, But if you want to have no such scale offsets in your project, you can also replace the camera icon with a suitable small one.
In Editor Preferences > Viewport: Decrease both: Mouse Scroll Camera Speed and Mouse Sensitivity To allow finer navigation at small scale
Note: A global scale conversion factor can be used instead of taking these measures, And in many cases this can be a more practical solution for managing a sub 50cm world, For example, building everything 100X size so that 1 meter will be representing 1 centimeter in your project’s world. But take into account, that if the project demands rendering realistic physical lighting and optics, extra conversions will have to be made to account for the scale conversion factor, so is such cases it may be better to setup a real-world scale project.
Note: This seems like an awkward workaround.. So if I missed something here, and there’s a better method to do this, I’ll be very grateful is you share it in the comments. Also, The following tip is only relevant for the CineCameraActor and won’t work with a regular CameraActor as it has a different built in offset (hopefully, I’ll have time to add this to the post later..)
Replacing the camera icon: Its fairly simple to replace the Camera component’s mesh icon, Just select the component and replace it’s Camera Mesh Static Mesh component with a different static mesh object:
So what’s the problem? The problem is that the default mesh used for the camera icon doesn’t have its natural pivot at the focal point of the camera, but at its bottom somewhere, And there is a hardcoded transform offset that compensates for that and places the icon mesh in a way that has the Icon lens roughly at the actual Camera actor pivot / focal point:
* I haven’t found any exposed transform parameter that allows moving the icon itself without moving the camera. So in-order to replace the camera mesh with an alternative icon mesh, and have it be aligned properly to the camera’s pivot / focal point (without changing engine code and building it) the built-in offset must be negatively pre-added to the new mesh model:
In this example in Blender, a new icon is modeled facing positive Y, with pre-built offset to compensate for the hardcoded offset in UE.